Flight Distance Research Articles

Flight Initiation Distance in an Urban Bird: Influence of the Number of People, Gaze Orientation, and Bird Behavior

Background: The flight initiation distance (FID) measures the distance a bird flees from an approaching predator. Factors such as the frequency of predator approaches, the direction of predator gaze, variations in predator presence across different areas, and the specific behaviors displayed by predators can all affect the FID. For birds, people can assume the role of predators. Methods: This study aimed to evaluate whether the FID of the species Sicalis flaveola (Saffron finch, Aves, Passeriformes) is influenced by the number of people and their gaze direction, comparing areas with the greater and lesser flow of people and relating to the types of behavior exhibited by the birds. Results: The results showed that the number of people walking towards the bird influenced the escape behavior, with more people generating longer FIDs than fewer people. If the approach was with the eyes fixed on the birds, the FIDs were longer. When birds were alert, FIDs were longer. Conclusion: Overall, the findings imply that birds exhibit nuanced reactions to human presence, even in areas with frequent human encounters, highlighting their advanced capacity for assessing and responding to perceived risks.

Captures do not affect escape response to humans in Alpine marmot

Capture and manipulation are an integral part of wildlife research and management. These practices, however, can affect animals either directly or indirectly, and studies should generally evaluate the consequences of captures to ensure animal welfare and reduce sampling bias. Here, we investigated the indirect, behavioural effects of live‐capture on escape response to humans in Alpine marmot Marmota marmota within the Stelvio National Park (central Italian Alps) over three seasons (2021–2023). We used flight initiation distance (FID) as a measure of escape response and tested it in relation to capture status using linear mixed modelling. Captures did not have any detectable effect on escape response, and FID was best explained by covariates such as starting distance, distance to nearest burrow, current behaviour during the observation and year of observation. It might be that, in marmots, escape response to humans is a rather inert behaviour. As such, although we cannot rule out unmeasured effects, capture may not represent an excessively traumatic experience which could trigger immediate behavioural modification. In turn, capture is unlikely to compromise animal welfare or cause scientific bias in studies investigating escape response in this species, at least over the short term.

Adaptive patterns of anti-predator escape behavior in a globally introduced bird species

Introduced species can represent quasi-experimental, anthropogenic case studies of both ecological and evolutionary principles. When these species are firmly established, competitive interactions between native and introduced species interactions, including foraging, spacing, and breeding competition, may be among the ecological costs incurred from such species invasions. In turn, genetic and/or plasticity-driven changes in behavior and morphology could also take place in the invading species with increasing introduction lag (time since the onset of introduction). Critically, however, introduction lag is difficult to study in any single non-native population without long-term observations, and, instead, it requires geographically repeated measures of the focal response variables across invasive populations that were introduced at different times. Here we tested a priori predictors of predator-avoidance behaviors through the flight initiation distance (FID) assay of a widely distributed invasive bird species, the common myna Acridotheres tristis. The species was extensively and consistently sampled throughout most of its independently introduced ranges across all hemispheres. Critically, FID increased with greater introduction lag. We also detected additional functional patterns in that FID increased towards the rural range within a continuous metric of urban-rural gradient and also at shorter distances from the Equator. Any robust study of FID must also include proximate predictors as well and, accordingly, we found that FID increased with greater starting distance, with lower immediate human density, with flighted over walking escape responses, and at lower heights of a bird’s perch above ground but was unrelated to myna group size. Respectively, these factors are informative about the sensory cues triggering anti-predator behaviors in invasive mynas and imply an adaptive set of patterns of anti-predator responses in the introduced ranges of this species. Control measures of invasive common myna populations should take into account their extensive behavioral and cognitive flexibilities and adjust the planned management methods accordingly.

Reliability of Spatiotemporal Characteristics During Single-Legged Hop and Bilateral Drop Jump Tasks Using an Instrumented Pressure Walkway.

Single-legged hop tests have been widely used to assess performance-based outcomes after anterior cruciate ligament (ACL) reconstruction. Traditional single, triple, or 6-meter (6m) timed hop tests only measure distance or time as the principal variables, neglecting other variables, such as individual hop distances within a series of hops, flight time, and stance time. The development of portable instrumented pressure walkways has made it possible to collect parameters such as hop velocity, flight time, stance time, distance, and pressure outside of a laboratory setting. However, the reliability of instrumented pressure walkways in measuring spatial and temporal variables during single-legged hop tests is unknown. This study aimed to determine if the Zeno walkway can reliably measure spatiotemporal (ST) characteristics of hop tests. Cross-Sectional Study. Individuals (n=38) in this cross-sectional study performed single, triple, and 6m hop tests on a pressure-sensitive Zeno walkway. Twenty-one participants completed follow-up testing between one and 14 days later. Intraclass correlation coefficients (ICC(3,k)) were used to assess test-retest reliability of ST variables. The accuracy of vertical jump height and 6m hop timing were also measured. All ST variables demonstrated excellent test-retest reliability (ICC > 0.86) with small minimal detectable change (MDC) values during single-legged hop tests. Six-meter hop time and jump height during a bilateral drop jump were also accurately measured by the walkway. An instrumented pressure walkway is a novel tool to reliably assess non-traditional parameters of clinically relevant hop and jump tests such as flight time, stance time, and jump height after lower extremity injury, surgery, and rehabilitation. 3b.

Systematic Research and Application of a 5G Medical Unmanned Aerial Vehicle to Deliver COVID-19 Nucleic Acid Samples.

The purpose of this study was to investigate the feasibility and effectiveness of COVID-19 throat swab samples delivered by medical drones in epidemic prevention and control. This study was carried out in both southern and northern hospital districts of the Affiliated Hospital of Jiangnan University from May to October 2022. The main participants were the Affiliated Hospital of Jiangnan University and Zhejiang Antwork Technology Co., Ltd. We first constructed an urban medical unmanned aerial vehicle (UAV) delivery system and developed a UAV-specific storage box for COVID-19 samples. The UAV system was used to transport COVID-19 throat swab samples from the northern hospital district to the southern hospital district, and the following indexes were obtained: (1) flight time of COVID-19 samples delivered by UAV, (2) real-time temperature of COVID-19 nucleic acid samples during transportation, and (3) the time of distribution of COVID-19 nucleic acid samples by road traffic as measured using the Baidu Maps application, compared with the flight time of UAV. The COVID-19 sample delivery system for urban medical UAV mainly consists of intelligent logistics UAV, low-temperature COVID-19 throat swab sample storage box, unmanned logistics hub, and cloud operation control platform. The flight distance between the northern and southern districts of the Affiliated Hospital of Jiangnan University was 10 km, and the ground distance was 24 km. From May 11 to October 28, 2022, a total of 1,190 UAV flights occurred. The average flight time was 13 minutes, which was 40 to 70 minutes faster than the average road travel time required for manual delivery of COVID-19 throat swab samples. At different time points in the day, UAV delivery efficiency increased by 67.5% to 82%. The use of 5G with the Internet of Things and UAV technology to deliver nucleic acid samples has the characteristics of fast speed, being unaffected by ground traffic conditions, and the ability to ensure the safety of nucleic acid samples in the transportation process, which is worthy of further study.

Who is your prenatal care provider? An algorithm to identify the predominant prenatal care provider with claims data.

Using claims data to identify a predominant prenatal care (PNC) provider is not always straightforward, but it is essential for assessing access, cost, and outcomes. Previous algorithms applied plurality (providing the most visits) and majority (providing majority of visits) to identify the predominant provider in primary care setting, but they lacked visit sequence information. This study proposes an algorithm that includes both PNC frequency and sequence information to identify the predominant provider and estimates the percentage of identified predominant providers. Additionally, differences in travel distances to the predominant and nearest provider are compared. The dataset used for this study consisted of 108,441 live births and 2,155,076 associated South Carolina Medicaid claims from 2015-2018. Analysis focused on patients who were continuously enrolled throughout their pregnancy and had any PNC visit, resulting in 32,609 pregnancies. PNC visits were identified with diagnosis and procedure codes and specialty within the estimated gestational age. To classify PNC providers, seven subgroups were created based on PNC frequency and sequence information. The algorithm was developed by considering both the frequency and sequence information. Percentage of identified predominant providers was reported. Chi-square tests were conducted to assess whether the probability of being identified as a predominant provider for a specific subgroup differed from that of the reference group (who provided majority of all PNC). Paired t-tests were used to examine differences in travel distance. Pregnancies in the sample had an average of 7.86 PNC visits. Fewer than 30% of the sample had an exclusive provider. By applying PNC frequency information, a predominant provider can be identified for 81% of pregnancies. After adding sequential information, a predominant provider can be identified for 92% of pregnancies. Distance was significantly longer for pregnant individuals traveling to the identified predominant provider (an average of 5 miles) than to the nearest provider. Inclusion of PNC sequential information in the algorithm has increased the proportion of identifiable predominant providers by 11%. Applying this algorithm reveals a longer distance for pregnant individuals travelling to their predominant provider than to the nearest provider.

Global aviation contrail climate effects from 2019 to 2021

Abstract. The current best-estimate of the global annual mean radiative forcing (RF) attributable to contrail cirrus is thought to be 3 times larger than the RF from aviation's cumulative CO2 emissions. Here, we simulate the global contrail RF for 2019–2021 using reanalysis weather data and improved engine emission estimates along actual flight trajectories derived from Automatic Dependent Surveillance–Broadcast telemetry. Our 2019 global annual mean contrail net RF (62.1 mW m−2) is 44 % lower than current best estimates for 2018 (111 [33, 189] mW m−2, 95 % confidence interval). Regionally, the contrail net RF is largest over Europe (876 mW m−2) and the USA (414 mW m−2), while the RF values over East Asia (64 mW m−2) and China (62 mW m−2) are close to the global average, because fewer flights in these regions form persistent contrails resulting from lower cruise altitudes and limited ice supersaturated regions in the subtropics due to the Hadley Circulation. Globally, COVID-19 reduced the flight distance flown and contrail net RF in 2020 (−43 % and −56 %, respectively, relative to 2019) and 2021 (−31 % and −49 %, respectively) with significant regional variations. Around 14 % of all flights in 2019 formed a contrail with a net warming effect, yet only 2 % of all flights caused 80 % of the annual contrail energy forcing. The spatiotemporal patterns of the most strongly warming and cooling contrail segments can be attributed to flight scheduling, engine particle number emissions, tropopause height, and background radiation fields. Our contrail RF estimates are most sensitive to corrections applied to the global humidity fields, followed by assumptions on the engine particle number emissions, and are least sensitive to radiative heating effects on the contrail plume and contrail–contrail overlapping. Using this sensitivity analysis, we estimate that the 2019 global contrail net RF could range between 34.8 and 74.8 mW m−2.

Three-Dimensional Path Planning for Post-Disaster Rescue UAV by Integrating Improved Grey Wolf Optimizer and Artificial Potential Field Method

The path planning of unmanned aerial vehicles (UAVs) is crucial in UAV search and rescue operations to ensure efficient and safe search activities. However, most existing path planning algorithms are not suitable for post-disaster mountain rescue mission scenarios. Therefore, this paper proposes the IGWO-IAPF algorithm based on the fusion of the improved grey wolf optimizer (GWO) and the improved artificial potential field (APF) algorithm. This algorithm builds upon the grey wolf optimizer and introduces several improvements. Firstly, a nonlinear adjustment strategy for control parameters is proposed to balance the global and local search capabilities of the algorithm. Secondly, an optimized individual position update strategy is employed to coordinate the algorithm’s search ability and reduce the probability of falling into local optima. Additionally, a waypoint attraction force is incorporated into the traditional artificial potential field algorithm based on the force field to fulfill the requirements of three-dimensional path planning and further reduce the probability of falling into local optima. The IGWO is used to generate an initial path, where each point is assigned an attraction force, and then the IAPF is utilized for subsequent path planning. The simulation results demonstrate that the improved IGWO exhibits approximately a 60% improvement in convergence compared to the conventional GWO. Furthermore, the integrated IGWO-IAPF algorithm shows an approximately 10% improvement in path planning effectiveness compared to other traditional algorithms. It possesses characteristics such as shorter flight distance and higher safety, making it suitable for meeting the requirements of post-disaster rescue missions.

Good Handling Practices Have Positive Impacts on Dairy Calf Welfare

The objective was to evaluate the effects of good handling practices on dairy calf welfare. Forty-eight crossbred dairy calves were assigned to two treatments: conventional handling (CH): calves kept in individual pens, fed milk replacer in buckets without nipples and abruptly weaned; or good handling practices (GHP): calves kept in group pens, fed milk replacer in buckets with nipples, given daily tactile stimulation during feeding, and progressive weaning. Calf welfare was assessed from birth to 120 days of age, based on: health (plasma concentrations of glucose and IgG, and occurrences of diarrhea, pneumonia, tick-borne disease, or death); physiology (heart rate [HR], respiratory rate [RR], and rectal temperature [RT]); behavior (flight distance [FD], latencies for first movement [LM] and to hold the calf in a pen corner [LH], and total time a calf allowed touching [TTT]); and performance indicators (body weight, average daily gain, and weaning success at 70 days of age). Calves in the GHP treatment had a lower HR at 30 days of age, shorter FD and LH, longer TTT, and lower RR and RT than CH (p < 0.05). However, health, deaths and performance indicators did not differ (p > 0.05) between treatments. Based on various indicators, GHP improved dairy calf welfare.

Machine Learning-assisted Distance Based Residual Energy Aware Clustering Algorithm for Energy Efficient Information Dissemination in Urban VANETs

A Vehicular Ad-hoc Network (VANET) is an essential component of intelligent transportation systems in the building of smart cities. A VANET is a self-configure high mobile and dynamic potential wireless ad-hoc network that joins all vehicle nodes in a smart city to provide in-vehicle infotainment services to city administrators and residents. In the smart city, the On-board Unit (OBU) of each vehicle has multiple onboard sensors that are used for data collection from the surrounding environment. One of the main issues in VANET is energy efficiency and balance because the small onboard sensors can’t be quickly recharged once installed on On-board Units (OBUs). Moreover, conserving energy stands out as a crucial challenge in VANET which is primarily contingent on the selection of Cluster Heads (CH) and the adopted packet routing strategy. To address this issue, this paper proposes distance and energy-aware clustering algorithms named SOMNNDP, which use a Self-Organizing Map Neural Network (SOMNN) machine learning technique to perform faster multi-hop data dissemination. Individual Euclidean distances and residual node energy are considered as mobility parameters throughout the cluster routing process to improve and balance the energy consumption among the participating vehicle nodes. This maximizes the lifetime of VANET by ensuring that all intermediate vehicle nodes use energy at approximately the same rate. Simulation findings demonstrate that SOMNNDP improves Quality of Service (QoS) better and consumes 17% and 14% less energy during cluster routing than distance and energy-aware variation of K-Means (KM) and Fuzzy C-Means (FCM) called KMDP and FCMDP respectively.

Automatically targeting the dorsolateral subthalamic nucleus for functional connectivity-guided rTMS therapy

Aim: Many resting-state functional magnetic resonance imaging (rs-fMRI) studies have provided evidence that repetitive transcranial magnetic stimulation (rTMS) exerts treatment effects via functional connectivity (FC) from a superficial stimulation target to a deep effective region. The dorsolateral subthalamic nucleus (DL-STN) is an effective target in deep brain stimulation surgery for Parkinson’s disease (PD), but its targeting highly depends on well-trained neurosurgeons and is not easily used for FC-guided rTMS. We aimed to devise a method for automatically localizing the DL-STN, and further develop a one-stop plug-in of rs-fMRI FC analysis to assist future individualized FC-guided rTMS. Methods: Based on structural and iron-sensitive MRI of 78 participants, two raters defined the DL-STN coordinates with very high reliability. The averaged coordinates in the standard Montreal Neurological Institute (MNI) space were: left DL-STN, x: -11.89 ± 0.82, y: -14.51 ± 1.00, and z: -6.40 ± 1.01 and the right DL-STN, x: 12.53 ± 0.77, y: -13.97 ± 0.86, and z: -6.57 ± 0.99. As the individual distances from the averaged coordinates were less than 3 mm (within one voxel for most rs-fMRI studies) for all 78 participants, we defined the average coordinates as AutoSTN. We then developed a one-stop plug-in named Connectivity and Coordinates Converting Assistant Toolbox (CC-CAT) and performed AutoSTN FC analysis. Results: The AutoSTN seed showed significant FC with the motor cortices in all participants. Conclusion: The AutoSTN-based rs-fMRI FC could guide future rTMS on PD. The one-stop plug-in CC-CAT can be used for any FC-guided rTMS treatment.

Femorotibial rotation is linearly associated with tibial tubercle-trochlear groove distance: A cadaveric study

ObjectivesA tibial tubercle-trochlear groove (TT-TG) distance of 20 millimeters (mm) is typically used when determining whether tibial tubercle medialization is performed for the surgical treatment of patellar instability. Without knowledge of how the variability of an individual's TT-TG distance is influenced by through-the-knee femorotibial rotation, the use of a specific TT-TG distance during preoperative planning for patellar instability may lead to incorrect decisions on the use of tibial tubercle medialization. We hypothesized that knee joint internal/external (IE) rotation is related to the TT-TG distance. MethodsEight independent human cadaveric knee specimens (age: 32 ​± ​6 years; 4 males, 4 females) were utilized. A robotic manipulator (ZX165U, Kawasaki Robotics, Wixom, MI, USA) instrumented with a universal force/moment sensor was used to determine knee joint IE rotation under applied moments of ±5 newton-meters (Nm) at full extension. Two independent reviewers selected the trochlear groove and tibial tuberosity points on computerized tomography (CT) images of each specimen to define TT-TG. To determine the influence of knee joint IE rotation on TT-TG distance, three-dimensional (3D) models generated from CT scans were registered to tibiofemoral kinematics. Linear regression was performed to determine the relationship between knee joint IE rotation and TT-TG distance. The regression coefficient, standard error of measurement (α ​= ​0.05), and coefficient of determination (r2) were reported. ResultsAt 0° of rotation, the mean TT-TG distance was 14.2 ​± ​5.0 ​mm. Knee joint IE rotation averaged 23.0 ​± ​4.2°. For every degree of knee joint IE rotation, TT-TG distance changed by 0.52 ​mm. ConclusionTT-TG distance was linearly dependent on knee joint IE rotation, changing by 0.52 ​mm for every degree of knee joint IE rotation. Thus, an offset of IE rotation of 10° would lead to a change in TT-TG distance of 5.2 ​mm, enough to alter the surgical decision-making for/or against tibial tubercle medialization. Level of Evidence: IVThis research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors.

Improved Driving Training-Based Optimization Algorithm Using Levy Flight and Crowding Distance Techniques

This study presents an improved version of the Driving Training-Based Optimization (DTBO) algorithm, the Improved Driving Training-Based Optimization (IDTBO). The work addresses fundamental issues in selecting drivers and learners for the conventional DTBO, which substantially impact the algorithm's accuracy and convergence speed. Two significant improvements are proposed: including the crowding distance technique for more diverse driver and learner selection and incorporating the Levy Flight distribution for better exploration and local optima avoidance. The IDTBO's performance is evaluated using twelve benchmark functions, including unimodal and high-dimensional multimodal optimization functions. The results indicate that IDTBO performs exceptionally well, with more extraordinary exploitation ability on unimodal functions and consistent achievement of the global optima. The proposed IDTBO demonstrated exceptional exploration capabilities on high-dimensional multimodal functions and performed competitively with other algorithms in the literature. From six functions, the IDTBO obtained zero optimal values. Again, the rate of convergence analysis demonstrates that IDTBO finds optimal solutions in fewer iterations, demonstrating its capacity to balance exploration and exploitation. To assess the strength of the IDTBO in solving real-world problems, the improved DTBO is further tested on two practical benchmark engineering problems. The IDTBO again produced a competitive performance against other algorithms in the literature. The study shows that IDTBO is a valuable metaheuristic algorithm that can tackle various real-world optimization problems.

Formation of flight zones of UAV according to the degree of stability in order to increase the reliability of the command radio control line in the conditions of the use of air defense and electronic suppression

The combat use of small and medium-class unmanned aerial vehicles (UAVs) in recent local military conflicts, as well as the experience of using UAVs in the operation of the Russian Aerospace Forces in Syria and Ukraine, has shown that they are mainly assigned the tasks of aerial reconnaissance in those areas of the theater of operations (Theater of Operations) where The use of manned aircraft is unjustified or impractical due to the high probability of damage to manned aircraft. The main threats to UAVs in modern theater are the possibility of hitting them with anti-aircraft missile systems (SAMs) of air defense (air defense), as well as the suppression of the command radio control line (CRU) of the UAV by means of electronic suppression (RAP) of the enemy. The purpose of the work is to develop theoretical solutions aimed at the formalized formation of air defense and RAP zones in the theater based on clustering theory methods for subsequent consideration of these zones in the automated formation of UAV flight routes. The paper proposes a methodology for the formalized formation of air defense and RAP zones based on the methods of clustering theory. In the future, the air defense and RAP zones are taken into account in the automated route control of the UAV by forming the flight route of the UAV bypassing these zones. The novelty of this solution, which distinguishes it from well–known works in the field of formation of UAV flight routes, is the consideration of two types of destabilizing factors as obstacles to UAV flight - the impact of air defense and REP means. These factors are formalized in the form of an integral metric of nodes in the graph of the geotopological model of the theater flight zone. At the same time, the Lance-Williams mathematical algorithm of hierarchical clustering is used to form «closed for flights» zones in which the probability of UAV damage is high, and areas of control violation due to the impact of RAP means. The connectivity check of the route network is based on the method of determining the strongly connected areas of the graph. The resulting solution makes it possible to increase the stability of UAV control during their combat use in theater equipped with air defense and RAP systems.

Nearest neighbour distance does not affect escape behaviour in urban hooded crows

The nearest-neighbour distance is an important property of a group, as individuals can obtain environmental information more quickly and easily from nearby individuals. We examined whether distance to the nearest neighbour affected two components of escape behaviour – alert distance (AD) and flight initiation distance (FID) – in an urban population of hooded crows Corvus cornix, while controlling for confounding variables. We did not find evidence that AD and FID were influenced by the nearest neighbour distance. However, both AD and FID were negatively affected by feeding activity of individuals – focal crows alerted later and escaped at shorter distance if they were feeding during our approach. In addition, AD and FID were positively related to starting distance and grass coverage. The lack of evidence for the nearest neighbour effect on escape behaviour of crows may be due to: (1) disturbance by close neighbours that may impede antipredator behaviour of focal birds, (2) variable distribution of familiar, dominant or experienced individuals within a flock, and (3) dynamic change in position of the nearest neighbour during the potential predator approach.

Guidance algorithm for reusable launch vehicle considering change in target

To address the design challenges of reentry guidance for high-speed aircraft in complex environments, and in response to the need for target adjustments during reentry, a method for designing reentry guidance laws with extended range has been introduced. The longitudinal guidance law has significantly improved real-time performance by converting infinite-dimensional optimization into a single-parameter search using the reentry flight corridor approach. The lateral guidance law employs line-of-sight angular deviation corridors to achieve target tracking, while the extended-range guidance law rapidly increases the flight distance of the reusable launch vehicle during the flight by optimizing attack angle profiles. Numerical simulations have been conducted to validate the effectiveness of the longitudinal, lateral, and extended-range guidance laws, indicating that they can meet the mission requirements for target adjustments during reentry.

Higher adaptive tolerance with higher risk for sparrows living in airport environments

Adjustments in flight initiation distance (FID) indicate how birds adapt to external environmental changes, including semi-natural ecosystems such as airports with regular disturbances. This study focused on sparrows (Passer montanus) as the research subject, because it is a dominant species with a high risk of bird strike events at airports. We investigated the FID and its influencing factors both inside and outside an airport compound to determine sparrows' vigilance and their adaptive adjustments to the airport environment. The FID of sparrows showed no significant variation between inside and outside the airport compound. However, a significant reduction of FID was exhibited during the breeding season. Group size showed a significant positive impact on the FID, somewhat supporting the many-eyes hypothesis, in which larger groups with more individuals may detect predators earlier. Additionally, the stimulus type and location influenced the effect of group size on FID, with most birds showing greater tolerance to vehicles than to humans, and being slightly bolder inside the airport than outside it. Overall, sparrows showed a higher tolerance to disturbance inside the airport compound and less vigilance to vehicles than to humans. Nevertheless, these adaptations may inadvertently form an ecological trap for bird populations around airports, exposing them to the dual threats of higher levels of raptor predation and the hazards of bird strikes. Thus multifaceted bird-scaring strategies and measures should be formulated to ensure flight safety and enhance avian survival during airport management.

Role of age, gender and cultural factors as moderator on technology acceptance of online entertainment

Purpose Research on technology acceptance of online entertainment with age, gender and cultural factors as moderator, is rarely conducted. Previous research predominantly focused on age or gender as moderator, neglecting the influence of cultural factors. Therefore, this study aims to investigate acceptance of online entertainment technology, incorporating age, gender and cultural factors as moderator. Design/methodology/approach Data were collected through a survey comprising 1,121 individuals aged 14–24 years from three cities in Indonesia. The proposed theoretical model examined the causal effect of acceptance and moderating effects due to individual gender, age, power distance, individualism, feminism and uncertainty avoidance (AU). Subsequently, structural equation modeling was used to evaluate the theoretical model, and the results confirmed several findings from previous research. Findings The findings confirmed the positive direct impact of habit and price value (PV) on behavioral intention and hedonic motivation, as well as social influence on habit. The recent findings derived from the moderating effect analysis showed that age, individualism and feminism played a moderating role in the effects on individual intention due to habit. Additionally, gender and AU moderated the effects on individual habits due to hedonic motivation. Originality/value This research contributes to the limited knowledge of technology acceptance of online entertainment, and also integrates the causal effects of individual intention due to habit, PV, hedonic motivation and social influence, considering the moderating role of culture, age and gender. Consequently, the investigation provides valuable insights into the literature by presenting evidence of age, gender and cultural differences in acceptance. Furthermore, it offers practical guidance to online entertainment application developers on designing applications to satisfy consumers of different ages, genders and cultures.

Golfers' Performance Is Improved More by Combining Foam Rolling and Dynamic Stretch to the Lead Hip Than Practice Golf Swinging.

Hamada, Y, Akasaka, K, Otsudo, T, Sawada, Y, Hattori, H, Kikuchi, Y, and Hall, T. Golfers' performance is improved more by combining foam rolling and dynamic stretch to the lead hip than practice golf swinging. J Strength Cond Res 38(7): e391-e397, 2024-Warming up is considered effective in improving performance and preventing injury. Despite this, there have been few studies investigating warm-up programs in golf and whether specific factors contribute to improved performance. The purpose of this study was to examine the immediate effects of combined foam rolling and dynamic stretch (FR + DS) to the lead hip on golf swing performance, hip range of motion (ROM), and muscle strength in amateur golfers using a randomized crossover design. The study sample comprised 22 men (mean ± SD ; age, 32.6 ± 8.5 years, body mass index (BMI), 23.4 ± 2.7 kg·m -2 ). Subjects were assigned to receive either FR + DS or repetitive golf swing practice (SW) before crossing over to the other intervention for another day. Measurements included golf swing performance (ball speed, club head speed, flight distance ["carry"], spin rate, and launch angle), hip internal rotation (IR), and external rotation (ER) ROM, as well as hip IR and ER muscle strength. Comparisons between groups were made before and after each intervention. For golf swing performance, FR + DS improved "carry" significantly more than SW ( p < 0.05). No significant differences in golf swing performance other than "carry" were found. In addition, IR ROM and IR muscle strength of the lead hip were significantly increased in the FR + DS group ( p < 0.05). FR + DS has effects on improving lead hip IR ROM and IR muscle strength, which may facilitate golfers' swing and "carry." FR + DS shows promise as a warm-up method for amateur golfers who want to improve golf performance.

Numerical simulation of postlaunching behaviors for a “balloon-borne UAV system”

PurposeThis paper aims to present numerical simulations for a series of flight processes for the postlaunching stage of the “balloon-borne UAV system.” It includes the balloon further ascent motion after airborne launching. In terms of unmanned aerial vehicles (UAVs), the tailspin state and the charge-out process with an anti-tailspin parachute-assisted suspending are analyzed. Then, the authors conduct trajectory optimization simulations for the long-distance gliding process.Design/methodology/approachThe balloon kinematics model and the parachute Kane multibody dynamic model are established. Using steady-state tailspin to reduced-order analysis and achieving change-out simulation by parachute suspension dynamic model. A reentry optimization control problem is developed and the Radau pseudo-spectral method is used to calculate the glide trajectory.FindingsThe established dynamic model and trajectory optimization method can effectively simulate the motion process of balloons and UAVs. The system mass reduction for launching UAVs will not cause damage to the balloon structure. The anti-tailspin parachute can reduce the UAV attack angles effectively. The UAV can glide to the designated target position by adjusting the attack angle and sideslip angle. The farthest flight distance after launching from 20 km height is 94 km and the gliding time is 40 min, which demonstrates the potential application advantage of high-altitude launching.Practical implicationsThe research content and related conclusions of this article achieve a closed-loop analysis of the flight mission chain for the “balloon-borne UAV system,” which provides simulation references for relevant balloon launching experiments.Originality/valueThis paper establishes a complete set of numerical simulation models and can effectively analyze various postlaunching behaviors.